With radio control, programming decoder CVs has been concern. I've previously explained that RAPA (the Radio Programming Adapter) can be used to write CVs by radio.The question is this:Can we use RAPA to read CV values? The answer is yes, by using the setup illustrated in the following photo.

The green circuit board is RAPA and a 6-wire, 2-way splitter is plugged into RAPA's PowerCab socket. RAPA also requires a 12 volt DC power supply. The small shrink-wrapped object in center of photo is an S-CAB radio-ready decoder. The splitter allows PowerCab to communicate radio commands via RAPA and at the same time connect to the decoder through its red/black wires (the right and left rail inputs in conventional thru-the-track DCC).

To perform CV programming, a motor must be connected to decoder orange/gray wires. When RAPA power is turned on, PowerCAB boots up and begins DCC output. It's best to send a few speed commands to be sure radio communication is good and the motor responds correctly. Now press PowerCab's 'PROG' button repeatedly until 'Programming Track' is displayed. Press 'ENTER', then '2' to select a CV number. Enter a number, press 'ENTER' and, after a brief pause, PowerCab will display the selected CV's value. At this point, either press 'ENTER' to escape or enter a desired value followed by 'ENTER' to change the CV value.

This brief explanation is certainly not an adequate set of instructions for reading/writing CV values. I just want to make it clear that S-CAB radio-ready decoders and RAPA now offer the same CV programming features as are available using a DCC programming track. We can read CVs just as easily as writing them.

Here's a photo of an NCE D13SR decoder before and after addition of the S-CAB radio receiver. By placing the antenna cross-wise we get a smaller package. With receiver and decoder mounted back-to-back, the result is thicker (0.32"), but length (1.5") and width (0.75") are not much bigger than the decoder.

Mounting the antenna in this manner is not recommended by the radio manufacturer. However, tests show good radio reception (at least 20 foot range), which is adequate for loco control. In future, this configuration will be available with no change in list price.

I plan to test this same antenna arrangement with Tsunami TSU-1000 and TSU-750 sound decoders. Because of its small size and simpler wiring, the 750 is a particularly good candidate for a minimum sized sound package.

This website reflects my lifetime interest in model railroading and technology. As a modeler, I built and rebuilt layouts that did not run trains to my satisfaction. As an electrical engineer, I watched technology progress much faster than its application to model railroading. So I looked for a better way, (which is what engineers are supposed to do) and ended up installing batteries in locomotives (actually electric multiple units, EMUs) and controlling trains by radio.

Berg's Hobbies model of Sydney Suburban EMU

Since I viewed radio control and battery power as important technology, but with small model railroading markets, manufacturing products was not the plan. However, I saw benefit by explaining what I was doing and published a series of articles, "Sydney Suburban Retrofit", in the Australian Model Railway Magazine, beginning in August 2009.

Stanton Drive with Berg's sideframes

The retrofit project actually led to design of an under-floor powered truck needed to clear the passenger compartment for something other than a motor. That's how I linked up with David Rygmyr after he purchased Northwest Short Lines (NWSL). Dave was receptive to replacing NWSL's venerable PDT ("pretty darn tiny") powered truck, which is how Stanton Drive became an NWSL product.

The first working prototype of radio throttle

Peter Berg, owner of Berg's Hobbies, who had seen my battery power and radio control ideas prototyped in his Sydney Suburban models, encouraged me to "productize" the home-grown radio throttle. He liked its simplicity from a user perspective and suggested I repackage it into something more marketable. So began S-CAB.

Author

I'm a retired electrical engineer, but still spending more time on engineering than on my layout. These days, it's mostly about applying radio control and battery power on smaller scale layouts (HO, On3, On30)